Difference Between Biodegradable and Compostable

Environment is a system, which is composed of living and non-living matters. Classification of environmental resources is a broad topic, as it depends on various factors. Degradation is one such key used to categorize environmental resources and their recyclability. Degradation can be further subdivided into numerous categories such as biodegradable and non-biodegradable, rapid degradation and slow degradation etc. some of the biodegradable wastes are considered as compostable. This article will provide some basic information about bio degradability and compostability and the differences between those two.

What is biodegradability?

Materials can be degraded biologically, chemically or physically. Biodegradable materials are degraded by reactions of living organisms. Generally, those materials have plant or animal origin. Some of the common examples for biodegradable materials are food, green waste (plant materials), manure and municipal solid waste. Some of the plastics are also biodegradable, whereas most of them are not, and this process of chemical dissolution can be done by bacteria or other biological means. Those organisms have the natural ability to degrade, convert or accumulate a huge range of compounds mainly organic substances. The degradation of those materials can occur under aerobic (with the presence of oxygen) conditions or anaerobic conditions, where the oxygen supply is very much limited. The final products after the process heavily depend on these conditions. There is an ample amount of uses, which can be obtained through the process of biodegradation of wastes. Preparation of bio fuel has become a novel technique to substitute energy requirement. Also, composting is done using biodegradable wastes subjecting them to several processing steps. Most of the environmental products are made by using materials that can decompose biologically into their natural elements. Not only the uses but also those biodegradable wastes can cause several environmental problems by releasing methane under anaerobic conditions. Accumulation of landfills of urban solid waste is the primary root for that. Studied had proved that biodegradation can be enhanced by natural secretions of microbes called extracellular surfactants.

What is compostability?

Compost is more related to organic farming, which is a new trend in modern agriculture. Compostability is the ability of converting materials in to compost. It depends on the characteristics of the given material and the provided conditions. While the internal characters such as C : N ratio, water content, and other chemicals are affecting the compostability, external environmental conditions (temperature, aeration, soil microorganisms etc) will affect too. Composting materials are also biodegradable organic matter but commonly result in fertilizer or some other soil amendment. Preparation of compost is not a single step process, but it consists of multi steps. Because of the steps used, method of compost preparation is varied. In some methods, wastes are piled up to decay whereas some other methods facilitate the same process by keeping them inside a pit in the ground or compost barrels. Normally it will take for about four to five weeks or even more to make them composted. It has to be watered, shaded, mixed, aerated and closely monitored. Carbon nitrogen ratio of the mixture can be adjusted by fortifying with those nutrients. Here, material breakdown occurs due to the activities of bacteria, actinomycetes, fungi, and other microorganisms and macro organisms such as earthworms. Compost is useful in soil fertilization. When it is added to the soil, the fertility of the soil will be improved due to a high content of available nutrients.

What is the difference between Biodegradability and Compostability?

• Compostability is one of the characteristics of some biodegradable materials, but not all the biodegradable materials are compostable.

• Some of the common compostable materials are green manure, animal manure, and some selected solid wastes.

• Biodegraded materials may have incorporated some toxins, but composts do not.

• Composting is done under aerated conditions while biodegradation can occur under both aerobic and anaerobic conditions.

• Some chemical parameters such as C : N ratio should be maintained in compostable materials whilst all the other biodegradable wastes do not.